Hybrid, electric, and fuel cell vehicles generally employ a high voltage electrical system, which includes at least one high voltage power source, such as a battery, a fuel cell, a generator, or the like. Before a person (e.g., a technician) may make physical contact with a current-carrying component of the electrical system (e.g., the interlock connection terminals), the high voltage power source should be disconnected and any localized electrical energy discharged. For this reason, the high voltage electrical system may employ a high voltage interlock (HVIL) control circuit that initiates discharge (or disconnection) of the power source when attempted access to the interlock connection terminals is detected.
After an HVIL control circuit has initiated discharge of the high voltage power source, a few seconds may elapse before the high voltage power source is sufficiently discharged. It thus becomes desirable to equip a high voltage electrical system with at least one mechanical barrier (referred to herein as a time-delay feature) that prevents a technician from accessing the interlock connection terminals until discharge is complete. For example, one high voltage connection system employs a threaded fastener, which secures an access cover to a high voltage device. The threaded fastener is covered by a shroud, which is electrically coupled to an HVIL control circuit. To disconnect the threaded fastener and remove the access cover, a technician first moves the shroud to an open position. This is detected by the HVIL control circuit, which initiates disconnection and discharge of the high voltage power source. A few seconds elapse as the technician removes the threaded fastener thereby permitting the power source time to discharge to an acceptable level before the access cover is removed.
Although high voltage connection systems employing conventional time-delay features are generally effective, they are still limited in certain respects. For example, high voltage connection systems of the type described above (i.e., systems employing a threaded fastener to secure an access cover) do not require reinstallation of the fastener to reconnect the high voltage interlock connection. As a result, a technician may not reinstall the threaded fastener after servicing, which may render the time-delay feature ineffective when the high voltage terminals are again accessed at a later time.
It should thus be appreciated that it would be desirable to provide a high voltage connection system employing a time-delay feature that prevents access to the interlock connection terminals until the high voltage power source is substantially discharged. It would further be desirable if such a high voltage connection system required reinstallation of the time-delay feature to reconnect the interlock connection. Other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.